garageCube

I have been running M8 & MM on a 2012 MacBook Pro with 8GB RAM and 4-core i7 processor. I usually run multiple 720p video streams in M8->Syphon->MM for output to a single 1080p projector.

Performance is OK, but I think it is time to upgrade. I am staying on a mac, but considering a Mac Pro (coffee can) instead of a MacBook. What are the most important specs to ensure best performance?

1. cpu speed?
2. number of cores?
3. RAM?
4. video card? (and what is most important spec for video card?)

16 GB RAM is more than enough actually.
Number of cores is important if you use FFMPEG video playback (HAP or ProRes are decoded on the GPU by default, so not much happens on the CPU)
Graphics Card is quite important. Hopefully we found how to get the best of the AMD card on many outputs because drivers are not that good compared to nVidia ones.
The most annoying this with this MacPro (apart from its price) is the connections. Projectors connected to mini display ports are easiely disconnected by moving the cables a little bit.

thanks, very helpful advice.

I know what you mean about the display port. I usually use a small strip of gaffer tape to hold the connector in the socket during performances.